Gabapentin is a widely popular medication. There were 64 million prescriptions for it in the U.S. in 2016, up more than 60 percent in just four years.

Experts say gabapentin is beneficial for many. It was approved by the FDA to treat certain seizure disorders and some types of nerve pain, but doctors also use it for a host of other conditions like insomnia, migraines and anxiety.

So why is it becoming a black-market drug?

"I think that some individuals may say that they use it to get high, and others may say they use it and get a drowsy effect," said Dr. Rachel Vickers-Smith.

She wrote her dissertation on the misuse and abuse of gabapentin.

"We found a nearly 3,000 percent increase from 2008 to about 2014 in individuals reporting gabapentin abuse," said Vickers-Smith.

Experts say gabapentin is typically misused by substance abusers who mix it with other drugs.

Insler says it's also possible for people with legitimate prescriptions to misuse, too.

"If somebody's taking excessively high doses or needing early refills," she said.

A recent New England Journal of Medicine letter also warns that "clinicians who are desperate for alternatives to opioids" are "increasingly prescribing gabapentin." And "evidence suggests that some patients misuse, abuse or divert gabapentin."

"I think that's why it's really important to get out the message," said Rachel Vickers-Smith.

A quick online search quickly turned up people talking about using 'johnnys.' But there was little information on potential abuse. However, the National Institute on Drug Abuse pointed to existing research, and the DEA says it is just beginning to receive calls.

Experts stress that gabapentin abuse is not the next opioid epidemic, but they believe it is something to watch closely.

NBC12 contacted two of the manufacturers of gabapentin, including Pfizer, which told us: "gabapentin is an important treatment option for their approved indications."